Siemens SIMOTICS S-1FK2 Configuration Manual page 78

Configuration
5.4 Brake resistances (armature short-circuit braking)
Calculating the braking time
The values for calculation are provided in Chapter "Data sheets and characteristics (Page 95)".
Braking time
Moment of iner‐
tia
Note
In determining the run-on distance, consider the friction of the mechanical transmission
elements (included in the calculation as an allowance in M
contactors.
To avoid mechanical damage to the drive, mount mechanical stops at the end of the absolute
traversing range of the machine axes.
76
t = J • n / (9.55 • M )
B tot Br
J = J + J
Tot Mot Ext
t / s = braking time
B
n / r/min = operating speed
M / Nm = average braking torque
Br
J / kgm = moment of inertia
2
Tot
J / kgm = motor moment of inertia
2
Mot
J / kgm = external moment of inertia
2
Ext
) and the switching delay times of the
B
1FK2 Synchronous Motors for SINAMICS S120
Configuration Manual, 02/2022, A5E46927724B AD